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Monday, May 7, 2018

New test could tell doctors whether patients will respond to chemotherapy

Purdue: Less than half the patients diagnosed with cancer
respond favorably to chemotherapy, but a new method for testing how
patients will respond to various drugs could pave the way for more
personalized treatment. Using Doppler light scattering, like a weather
radar, researchers can determine how a patient will respond to
chemotherapy even before they begin treatment. “Doppler weather radar sends electromagnetic
waves into clouds, and while you don’t see individual rain droplets, you
pick up the overall motion of the raindrops. What you create with this
is a 3-D map of cloud motion,” said David Nolte, the Edward M. Purcell
Distinguished Professor of Physics and Astronomy at Purdue University.
“We’re looking at the motion inside living tissue rather than rain
droplets, and we’re using infrared light instead of radar. It’s like
watching the weather inside living tissue as the tissue is affected by
cancer drugs.”

Tiny chunks of tissue taken from a biopsy are
placed in a multiwall plate, where various drugs are applied. Light from
an LED shines into the middle of the tissue, and researchers look at
the scattered light coming off.

In collaboration with John Turek, professor of
basical medical sciences, and Mike Childress, associate professor of
veterinary medicine, Nolte has built a library of data to associate
various light patterns with the corresponding response of patients to
treatment.

The findings,
which were published in the journal Biomedical Optics Express, report
an 84 percent success rate predicting patient response to therapy in the
group’s first complete pre-clinical trial.

The study was performed on 19 dogs previously
diagnosed with B-cell lymphoma, which is molecularly and clinically
similar to lymphoma in humans. The treatment of cancer in dogs is almost
identical to treatment for humans, Nolte said. They have biopsies, go
through chemotherapy and come back for follow-ups.

The method for testing patient response to
therapy, biodynamic digital holography, is currently in clinical trials
in human ovarian, breast and esophageal cancer. These trials are
proceeding with similar levels of accuracy, Nolte said.

“This could revolutionize the way chemotherapy is
selected for patients. Hundreds of thousands of patients per year are
given standard treatments, while only 40 percent of them actually
respond,” he said. “Currently, there’s no good way to personalize
treatment because there’s no evidence-based medicine that doctors can
turn to. If our method works in human cancers, it means we can help
doctors choose better therapies.”

Attempts to create strategies for predicting
patient response to chemotherapy have been made in the past. These older
methods broke up tumors into individual cells and re-grew them as
2-dimensional cell cultures. This destroyed the cellular environment in
which a tumor exists, which contributes significantly to its response to
treatment. By preserving the cancer environment in living 3-D biopsies,
Nolte’s team is able to assess how cells respond to drugs in the
relevant environment.

The study was funded by grants from the National
Science Foundation (1263753-CBET), National Institutes of Health
(R01-EB016582) and seed grants from the Purdue University Center for
Cancer Research (PUCC).

Nolte and Turek have financial interest in
Animated Dynamics, which has licensed biodynamic technology from the
Office of Technology Commercialization at Purdue.